Miscarriage is a  spontaneous or unplanned expulsion of a fetus from the womb usually before 20^th week of pregnancy due to different genetic abnormalities or various medical reasons such as: infections, diabetes, hormonal problems, thyroid disease, consumption of alcohol, smoking and other risk factors increasing  chances of having any of the types of miscarriage.

• Complete Miscarriage - when all pregnancy tissues have been expelled from your body. Complete miscarriage shows signs such as severe and extreme pain in the abdominal part, heavy vaginal bleeding and entire expulsion of conception products. With a complete miscarriage, the bleeding and pain should subside quickly. This type of miscarriage can be confirmed through an ultrasound.
• Incomplete Miscarriage -  symptoms of incomplete pregnancy are as same as the complete one is accompanied with including excessive pain, severe bleeding and cervix remaining open. However, when it comes to incomplete miscarriage, some - but not all - of the pregnancy tissues are passed. In case of incomplete miscarriage, it it necessary to remove remaining tissues through medical procedures. 
• Missed Miscarriage - if you experience a missed miscarriage, you might have a brownish discharge. It is a condition when a fetus dies but instead of being expelled from body, it remains in uterus. 
• Threatened Miscarriage - the pre-condition when bleeding and cramps point to a possible upcoming miscarriage.  You might have bleeding or lower abdominal pain while cervix remains closed. It can last either days or weeks. 

In some cases a miscarriage can occur before even knowing about pregnancy. In addition, as with your menstrual period, some of the symptoms of a miscarriage involve bleeding and cramping.

So how can a miscarriage and period be distinguished?

When trying to differentiate between a period and a miscarriage, there are several factors to take into account:

• Symptoms: Severe or worsening back or abdominal pain as well as passing fluids and large clots could be a sign a miscarriage rather than a period.
• Time-frame: A miscarriage in a very early stage of pregnancy can be mistaken for a period. However, this is less likely after approximately 8 weeks into a pregnancy.
• Duration of symptoms: The symptoms of a miscarriage typically get worse and last longer than a period.

If you’re experiencing heavy bleeding or believe that you’re having any type of miscarriage, call emergency or contact your doctor immediately.